AVI + Audio = Really Ugly Babies

thegamefreak0134 · Post by **thegamefreak0134** » Thu 08 Feb, 2007 7:58 am

I have a rather lengthy AVI file on my computer that is ripped (sort of legally, from a disc I own) from a DVD. The movie is well over an hour in length, and the picture quality is rather excellent. However, I notice that as the movie plays along, the picture gets more and more out of sync with the audio. It doesn't seem like the "compressed" DVD encoding has any issues keeping its sound and video in sync, so why does this movie have issues like this?

What I really want is some way to reverse this process. If there was a way I could excract, and then replace the audio in the movie, I could edit it with my favorite sound editor and "stretch" it ever so slightly so it was the same length as the video, which would hopefully fix my problems. (It gets in the neghborhood of a few seconds off from the video toward the end.) Or could this possibly be a problem with my AVI decoder? (Or the one for whatever codec it compresses with)

This is a particularly odd issue, one that it seems would've fixed itself by now in our modern world...

-thegamefreak

hop · Post by **hop** » Thu 08 Feb, 2007 8:10 am

Update your decoders.

Post by **tr1p1ea** » Thu 08 Feb, 2007 8:27 am

Try updating your decoders, if that doesnt work, download everyones favourite video editing tool VirtualDub (www.virtualdub.org) n which you can export the audio track to a WAV file where you can edit it later. You can even offset the audio by a fraction of a second at the start of the movie in VurtualDub, which might make all the difference in the end.

Post by **benryves** » Thu 08 Feb, 2007 11:20 am

Also make sure that the framerate is not higher than your video refresh rate. Most video clips are at sane rates (25Hz or so), but I know that clips that run at over 70Hz when my refresh rate is set to 60Hz cap at 60Hz, and so go out of synch.

hop · Post by **hop** » Thu 08 Feb, 2007 12:24 pm

VSync outside of games is silly though. Even in games.

Post by **benryves** » Thu 08 Feb, 2007 12:25 pm

So you like tearing?

hop · Post by **hop** » Thu 08 Feb, 2007 1:28 pm

If you're still using those silly refresh rates then you're killing your eyes so you won't be able to see the tearing anyway. ~_^

You're forced to render at lower rates than those vsynch applies to anyway, to prevent the audio from desynching, remember?

thegamefreak0134 · Post by **thegamefreak0134** » Thu 08 Feb, 2007 4:35 pm

Wow. I never would have expected framerate to be a real issue, considering that the normal framerate for movies in the USA is 29.75 fps. Although that might cause slight issues, I think, since it doesn't go very well into tearing, if my decoder forces a VSync or something...

Anywho, how does one go about updating ones video decoders? Windows does a pretty fair job of hiding the fact that they're even there, to the point that I have to use third party software to even see the ones installed on my machine. I will also look into this virtualdub thing, since it sounds usefull. Thanks!

-gamefreak

Post by **benryves** » Thu 08 Feb, 2007 5:05 pm

thegamefreak0134 wrote: Windows does a pretty fair job of hiding the fact that they're even there, to the point that I have to use third party software to even see the ones installed on my machine.

No, you don't. Go into Control Panel, open the Sounds and Audio Devices control panel. Go to the Hardware tab. Double-click on Audio Codecs or Video Codecs. Click on the "Properties" tab.

The DirectShow Filter Graph Editor (it's part of the DirectX SDK) is an invaluable tool for working with your DirectShow filters. It's handy for converting media files (eg, get it to render a Quick Time file, remove the sound and video rendering devices, run the sound through WavDest and the result of that through an Avi Mux with the video to a FileWriter).

If you're looking for extensive codec support, you can install both the K-Lite Codec Pack and the DirectShow Filter Pack.

thegamefreak0134 · Post by **thegamefreak0134** » Thu 08 Feb, 2007 10:12 pm

Well no wonder... I have the pinnacle avi codec installed. I've had issues with Pinnacle rendering stuff this way in the past, I just never imagined it would be the codec, I assumed the (older version of the) program just didn't handle avi files very well. It was designed primarily for DVDs anyway...

kk, Time to go find a new AVI codec. Wheeeee!

-thegamefreak

Post by **tr1p1ea** » Fri 09 Feb, 2007 9:13 am

Well the Combined Community Codec Pack is usually pretty good, obtainable from here: http://www.cccp-project.net/